Method of and apparatus for electroinductively heating metal billets



Dec. 13, 1966 F. SCHEFFLER 3,291,954

METHOD OF AND APPARATUS FOR ELECTRO-INDUCTIVELY HEATING METAL BILLETSFiled March 20, 1964 2 Sheets-Sheet l Dec. 13, 1966 F. SCHEFFLER3,291,954

METHOD OF AND APPARATUS FOR ELECTRO-INDUCTIVELY HEATING METAL BILLETSFiled March 20, 1964 2 Sheets-Sheet 2 United States Patent Germany, andAllgemeine Elektricitats-Gesellschaft, Berlin-Grunewald, Germany FiledMar. 20, 1964, Ser. No. 353,452 Claims priority, application Germany,Sept. 28, 1963, D 42 582 11 Claims. oi. 219--10.69)

The present invention relates to .a method of and apparatus forelectro-inductively heating metal billets.

When metal billets are heated it is often desirable that the hotbilletsshould be ready at given intervals for feeding a hot working machine orthe like without interruption. This requirement is generally impossibleto satisfactorily by using a furnace in which the billets are heated bygas, oil or electric resistors. It has therefore already been proposedto interpose in the supply line between such a furnace and the hotworking machine supplementary heating equipment which can be controlledin synchronism with the working cycle of the hot working machine. Theuse of induction heating equipment has already been proposed for thispurpose.

The present invention concerns plants for electro-inductively heatingmetal billets which are to be supplied to hot working machines or thelike at intervals which synchronise with a prescribed working cycle. Theproposed plant is distinguished by its particularly convenientconstruction which is extremely compact for solving the problem inquestion. The invention provides a billet-transporting roller bed withtiltable sections above which the inductors are located outside the pathof the roller bed. Alongside each tiltable section of the roller bed isa stand for supporting one inductor. The stands are also equipped with aslideway for a billet loading slide which is adapted to push the billetup the tilted roller bed section int-o the inductor interior .and tolower the same out of the inductor. Whilst the tiltable roller bedsection returns into the horizontal the slide retains the billet in theinductor.

The proposed plant permits the several inductors to be independentlyloaded and unloaded again without impeding the continued flow of billetsalong the roller bed. It is thus possible with due regard to therequired heating and reheating times that may be required to adjust theintervals at which the billets heated to hot working temperature, aredelivered in synchronism with the working cycle of a following hotworking machine. The roller bed need merely be provided with asufiicient number of inductors to permit operation in conformity withthe particular circumstances and factors that govern the working cycleof the production line. Moreover, a single preheating furnace may beassociated with a plurality of or with two roller beds arranged side byside and billets may be delivered to the several beds in rotation, forinstance by suitable gating means.

A preferred embodiment of the invention is illustratively shown in thedrawings in which FIG. 1 is a perspective view of a live roller bed,

FIG. 2 is a vertical section of the live roller bed directly behind oneof the tipping sections,

FIG. 3 is a side elevation of an inductor stand and FIG. 4 is a similarside elevation of a stand showing the loading slide and the billet inloaded or unloaded position.

An elongated base 1 carries a live roller bed 2, the several rollersbeing driven either individually or in groups in a manner that is wellunderstood. Sections 3 of the roller bed are adapted to tilt on trunnionbearings 4. The

3,291,954 Patented Dec. 13, 1966 tiltable sections are likewise fittedwith rollers which may be driven singly or in groups. Convenientlyfacilities are provided for driving the rollers in the tiltable sections3 at a speed which differs from that of the rollers in the rest of thelive roller bed.

Each tiltable section is equipped with an interceptor 5 which can betiltably raised on pivots 6. In chain dot outlines an interceptor isshown in raised position at 5 in FIG. 2. The purpose of the interceptoris to stop a billet travelling along the roller bed when it has beenconveyed on to the respective tiltable section. An intercepted billet isshown in chain dot lines at 7.

Alongside each tiltable section 3 is a stand '8 which carries aninductor 9. The inductor is so disposed that its opening .10 aligns withthe tiltably raised roller bed section 3.

Stand 8 also carries a slideway 11 for a billet loading slide 12. Theslideway is parallel to the axis of the associated inductor 9. Thebillet loading slide 12 has a lateral arm 14 with a pusher finger 13.

In FIG. 3 the billet loading slide 12 is shown in its upper position inwhich it holds a billet 7 inside inductor 9 where the billet can beheated to a required temperature. FIG. 3 also illustrates that thetiltable roller bed section 3 drops back int-o alignment with the restof the roller bed during this heating operation, so that the continuityof the roller bed is restored.

In FIG. 4 the loading slide .12 is shown in its bottom position. It willbe seen that the tiltable section 3 of the bed can then clear the slide12.

The illustrated arrangement which is intended for reheating metalbillets functions as follows:

In FIG. 1 it will be understood that a furnace is located at the righthand charging end of the roller bed. This may be, for example, anelectric resistance heating furnace for heating say steel billets forhot working to a temperature of something like 600. Each billet, afterhaving reached this temperature, is discharged on to the roller bedshown in FIG. 1. It is assumed that the billet has been propelled to thefirst inductor at the left hand forward end of the bed in FIG. 1. Herethe billet 7 is stopped on the associated tiltable roller bed section bythe interceptor 5. The reduce the impact the billet may be slightlybraked by the rollers in the tiltable section revolving at a slowerspeed than the rollers in the rest of the bed. The section 3 is thentilted into the position illustrated in FIG. 4. This is the sameposition as that which the tiltable section is seen to occupy at themiddle stand in FIG. 1. The pusher finger 13 of the billet loading slide12 can now be applied to the end of the billet to raise the same intothe interior of the inductor 9. The final loading position of the slide12 is that shown in FIG. 3. This is the billet heating position which isalso seen to have been established in the distant inductor on the rightin FIG. 1. The tilted roller bed section returns into the horizontalwhilst the interceptor 5 is raised into position 5. The next billetdischarged by the preheating furnace can therefore now pass underneaththe loaded inductor to another stand in which the inductor happens to beready to receive it. Alternatively, a heated billet can be carried pastthe loaded inductor stand to the hot working machine.

When the billet has been .sufiicientl-y heated by the inductor, thetiltable section is again tilted to receive the heated billet and theslide is lowered again to the position shown in FIG. 4. The tiltedsection is again returned into line with the bed, the interceptor whichhas been rendered operative prior to tilting the said section is againrendered inoperative and the billet heated by the inductor is carried onby the bed.

The heating times during which the loading slides remain in heatingposition, the tilting deflections of the tiltable roller bed sections,the raising and lowering of the inte-rceptors and the speed of travel onthe roller bed can be suitably synchronised by electric control meanscomprising timing relays and so forth in a manner well known to the art.

'What I claim is:

v1. Apparatus for electro-indnctively heating metal billets which arerequired to be delivered to hot-working apparatus or the like insynchronism with a predetermined working cycle, comprising abillet-transporting roller bed; said bed comprising a plurality ofsections each tiltable into an inclined position; an inductor locatedabove each tiltable section outside the path of travel of the billets onthe bed; and means for conveying a billet on a tilted section along saidsection and into cooperation with the inductor associated therewith andfor maintaining the said co-operation while the said tilted section isreturned into alignment with the bed to allow another billet to betransported past the said inductor.

2. Apparatus according to claim 1, comprising a displaceablebillet-interceptor on each said tiltable rollersection adapted to bedisplaced into intercepting position when the said section is to betilted with the intercepted billet and to be withdrawn when it isdesired that another billet shall pass oil. the said section when thisis co-linear with the bed.

3. Apparatus according to claim 1, comprising a pivotedbillet-interceptor on each tiltable section.

4. Apparatus for electr-o-inductively heating metal billets which arerequired to be delivered to a hot-working machine or the like insynchronism with a predetermined working cycle, comprising abillet-transporting roller bed, said bed comprising a plurality ofsections each tiltable into an inclined position, and inductor and asupport therefor alongside each tipping section, a billet loading slide,and means for guiding said slide for movement on said support, saidslide being adapted to push a billet up a tilted .section into theinterior of the saidind-uctor and to hold the billet in the interior ofthe inductor whilst the tilted section returns into alignment with therest of the roller bed, said slide being operable to lower the heaterbillet from the inductor to the bed.

5. Apparatus according to claim 1, comprising means for driving rollersof the bed for transporting the billets.

6. Apparatus according to claim 1, in which the bed comprises tiltableand non-tiltable sections and means for driving rollers on the bed fortransporting the billets.

7. Apparatus according to claim 1, in which the bed comprises tiltableand non-tiltable sections, means for driving rollers of non-tiltablesections of the bed, means for driving rollers of the tiltable sectionsof the bed and means for controlling the speed of notation of therollers on at least the tiltable sections of the bed.

8. Apparatus according to claim 1, in combination with a pre-heatingfurnace.

9. The method of electr-o-ind-uc'tively heating metal billets whichcomprises transporting billets along a roller bed provided with aplurality of sections each tiltable into an inclined positionperiodically tilting a said section with a billet located thereon, anddisplacing the said billet along said section into an induction heater,retaining the said billet in the said heater and returning the.

said tilted section into line with the bed and causing at least onefurther billet to pass along and beyond the said returned section whilethe said first billet remains in the heater and lowering said firstbillet when heated sulficiently again onto the bed in predeterminedtimed relation to the travel of billets along the bed and delivering theheated billet and hot-working it.

10. The method according to claim 9, in which a plurality of saidsections are provided and a said inductor is associated with each saidsection and while a billet is being heated in the heater associated witha first said section a further billet traverses this first section alongthe bed, said further billet being intercepted on a second tiltablesection of the bed and said second section tilted and said furtherbillet displaced into the inductor associated with the said secondsection.

11. The method of .electro-inductively heating metal billets whichcomprises transporting billets by means of a roller bed provided with aplurality of sections each tiltable into an inclined position,periodically tilting a said section with a billet located thereon anddisplacing the said billet along said section into an induction heater,retaining the said billet in the said heater and returning the saidtilted section into line with the bed and causing at least one furtherbillet to pass along and beyond the said returned section whilst thefirst said billet remains in the heater, again tilting the said sectionand receiving the heated billet from the inductor thereon and againreturning the said section into line with the bed and causing the saidheated billet to be carried on by the bed to a hot Working machine.

1. APPARATUS FOR ELECTRO-INDUCTIVELY HEATING METAL BILLTS WHICH AREREQUIRED TO BE DELIVERED TO HOT-WORKING APPARATUS OR THE LIKE INSYNCHRONISM WITH A PREDETERMINED WORKING CYCLE, COMPRISING ABILLER-TRANSPORTING ROLLER BED; SAID BED COMPRISING A PLURALITY OFSECTIONS EACH TITLTABLE INTO AN INCLINED POSITION; AN INDUCTOR LOCATEDABOVE EACH TILTABLE SECTION OUTSIDE THE PATH OF TRAVEL OF THE BILLETS ONTHE BED; AND MEANS FOR CONVEYING A BILLET ON A TILTED SECTION ALONG SAIDSECTION AND INTO COOPERATION WITH THE INDUCTOR ASSOCIATED THEREWITH ANDFOR MAINTAINING THE SAID CO-OPERATION WHILE THE SAID TILTED SECTION ISRETURNED INTO ALIGNMENT WITH THE BED TO ALLOW ANOTHER BILLET TO BETRANSPORTED PAST THE SAID INDUCTOR.